Editor’s note: This commentary is by Michael Shank and Matt Cartwright. Shank, of Brandon, teaches at NYU’s Center for Global Affairs and is the communications director for the Carbon Neutral Cities Alliance and the Urban Sustainability Directors Network. Cartwright represents Pennsylvania’s 17th congressional district and serves on the House Appropriations Committee.

The latest developments in the food industry show how fast the world is moving forward in countering climate change. In March, the global food chain giant McDonald’s announced that it is planning to cut its emissions intensity by 31 percent, across its supply chain, by 2030. That’s a big deal. It’s the first global restaurant company in the world to set a science-based target to reduce greenhouse gas emissions. If McDonald’s can lead on this, so should the United States.

We have an opportunity to do that. Unfortunately, it won’t be via the farm bill – one effective lever the U.S. government has to reduce food’s carbon footprint – which remains stalled in Congress again. It’s via the U.S. Department of Agriculture’s national dietary guidelines. We could use these guidelines to reduce food-based emissions. (The USDA has never been a close friend of climate action: it excluded the word “sustainability” from the previous National Dietary Guidelines.)

If the U.S. wants to reduce its food-based emissions, the USDA should follow the advice of their advisers. The USDA’s own Dietary Guidelines Advisory Committee, made up of federally appointed health experts, recommended an increase in plant-based diets three years ago based on both nutritional and sustainability concerns.

What should drive our nation’s dietary priorities must be good for both the American people and the planet – otherwise there’s no way to sustain it. And there is no question that a plant-based diet is key to sustainability and our survival.

Take a look at the evidence. On the production front, we know that a unit of beef protein contributes 150 times more greenhouse gas emissions than a unit of soy protein. Beef production also requires nearly 30 times more grazing land than pork or chicken production. That’s a whopper of a difference. Pork and chicken also have a heavy carbon footprint, coming in at 20 to 25 times heavier in greenhouse gases than soy.

But it’s not just what’s being farmed that impacts us all, it’s how products are being farmed. In comparison to conventional farming methods, organic farming produces gains in resource management and allocation. In fact, organic agriculture captures significantly more carbon than non-organic and industrial-scale farming, which are often much more water and resource intensive.

By avoiding pesticides, herbicides, hormones and genetic engineering, organic farming’s health and environmental benefits are also clear. Organic food is six times less likely to contain pesticide residues than food produced through conventional farming methods. And nationally, investing in organic agriculture means reducing costs associated with clean-up efforts in polluted water and soil from pesticides.

Add to this fact that adding more plant-based foods to one’s diet is much more economical, which is a critical consideration for many American shoppers and families with a tight food budget, and it becomes clear why nutrition and sustainability are inseparable. Plant-based proteins, such as beans and grains, are often the least expensive foods available and produce a smaller carbon footprint than meat alternatives.

As our population continues to grow (the U.S. has one of the fastest population growth rates in the developed world), we must think creatively and courageously about more sustainable diets and long-term food security. By 2050, we’ll need to increase food production by 70 percent to feed 9.7 billion people, according to the U.N.

At those rates, we simply do not have sufficient energy and water resources for a diet heavy in animal protein. Years ago, the USDA’s Advisory Committee pointed another path forward, and it’s one we must adopt now. The health of this country, and its heartland, is at stake.